Many NMR applications involve performing measurements at elevated temperatures. Such measurements typically require heating the samples of interest from ambient temperature to an elevated temperature of interest. In a common design approach, the sample of interest is heated by flowing a hot gas over a sample container positioned in an NMR probe. For descriptions of NMR systems and probes using gas-flow heating see for example U.S. Pat. Nos. 5,530,353,5,408,181, and 5,192,910. The gas-flow heating method may require minutes of waiting between measurements in order to allow the samples to come to thermal equilibrium at the desired elevated temperature. The waiting periods often limit system throughput.
In U.S. Pat. No. 5,300,888, Webster et al. describe an NMR probe including a non-inductive heating winding encapsulated within the probe wall. The temperature of a sample within the probe is presumably controlled by resistively heating the winding. A probe including a heating winding is also described by Webster et al. in the article "High Temperature .sup.1 H NMR Probe," Rev. Sci. Instrum. 50(3):390-391 (1979).
In the article "High-Temperature NMR using Inductive Heating," Rev. Sci. Instrum. 61(1):77-80 (1990), Maresch et al. describe heating an NMR sample by applying RF energy to a metal-coated sample tube. The applied RF energy heats the metal coating of the sample tube, which in turn heats the sample.